Stencil-stub clamp



July 13 1926. 1,592,439

E. J. BRASSEUR STENCIL STUB CLAIP Filed NOV. 19, 1924 2 Sheets-Sheet 1lNVENTOR ATTORNEY v July 13 1926. 1,592,439

E. J. BRASSEUR STENCIL STUB CLAMP Filed Nov. 19, 1924 2 Sheets-Sheet 2INVENTOR ATTORNEY Patented July 13, 1926.

UNITED STATES I 1,592,439 PATENT OFFICE.

ERNEST J. BRASSEUR, OF CHICAGO, ILLINOIS, ASSIGNOR TO A. B. DICKCOMPANY, OF

' CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

STENCIL-STUD CLAMP.

Application filed November 19, 1924. Serial No. 750,728.

This invention relates to a stencil stub clamp, and more particularlyrelates to an adjustable clamp for detachably clamplng the stubs ofstencil sheets in place on rotary duplicating machines.

Heretofore it has'been customary to provide rotary stencil duplicatingmachines with button bars and to rely solely upon the engagement of thebuttons in button holes in the stub of a stencil sheet and to hold thestub of the sheet on the machine. lVith certain kinds of stencil sheetsso much tension has been created at the buttons when the machineoperates that the stub tears away from the buttons and the sheet becomesdisplaced.

The principal aim of my invention 1s to provide auxiliary clamping meansfor clamping the stub of a stencil sheet to the button bar to supplementthe bar buttons in holding the sheet in place and to prevent stencilsheets of delicate material from tearing away or from becoming displacedfrom the button bar when the machine is operated. Another object of myinvention is to provide a clamp of the character described, and onewhich may be readily and easily adjust ed into and out of clampingposition. A further object of my invention 1s to provide clamping meansof the character described which are simple, durable and inexpensive inconstruction. Other objects of my invention will be in part obvious andin part pointed out hereinafter.

In accordance with my invention, as sup- Elementary attachment means tothe usual utton bar on rotary duplicating1 machines I mount adjacent tothe button ar one or more resilient clamps, and so design and mountthese clamps that by a simple manual operation the operator may movethese clamps over the button bar so as to clamp the stencil stub tightlyagainst the button bar, and by reversing the operation remove the clampfrom the button bar and stub.

In order that a clearer understanding of my invention may be had,attention is hereby directed to the accompanyin drawings forming a partof this applicatlon and i1- lustrating one possible embodiment of myinvention. Referring to the drawings, Fig. 1 is a front view, partly insection, of a portion of a stencil duplicating cylinder showing a pairof clamps embodyin my invention associated therewith, the 0 amp on theleft being shown in clamping position and the clamp on the right beingshown in disengaged position; Fig. 2is a perspective view of one of theclamps; Fig. 3 is a sectional view through a portion of the printingcylinder, showing one of the clamps in end view, the view being taken onthe line 33 of Fig. 1; Fig. 4 is an end view of the clamping meansshowing an intermediate position of a clamp and its relation to theutton bar and end of the stencil stub, these parts being shown insection; and Fig. 5 is a view similar to Fig. 4, but shows the clampingmeans in fully open position. Similar reference characters refer tosimilar parts throughout the several views of the drawings.

Referring to the drawings, there is shown a conventional cylinder 1 of arotary duplieating machine, the cylinder carrying a conventional buttonbar 2 provided with buttons 3 which are adapted to be removably engagedin the usual perforations 4. in the stub 5 of a stencil sheet 6. Thebutton bar at its center has a rearwardly projecting hub 7 which isperforated, as at 8, to permit a bolt 9 to be extended therethrough.

Between each side of hub 7 and a side of the cylinder 1 is pivoted aclamping device. Each clamping device consists of a U-shaped frame 10,one side wall, 11, of which is pivvoted on an end of bolt 9 and theotherside wall, 12, of which carries a pin 13 which rotatably engages ina perforation 13 in the side wall of the cylinder. Preferably, a cam 14is provided on the frame 10 adjacent the pin 13 and a coacting spring 15is mounted over the cam 14 against the underside of the flange 16 of thecylinder. Preferably, the ends of the spring 15 are engaged over pins 17carried on the cylinder, whereby the spring is held in place. Cam 14 isprovided with two flat faces 18 and 19, one of which, 18, is positionedto be flat against the spring 15 when the clamp is fully open and theother face, 19, of the cam is adapted to be flat against the spring whenthe clamp is engaged with the button bar and stencil stub. In this waythe spring tends to hold the clamp in either extreme position.

From the above it is apparent that each frame 10 is pivoted on thecylinder at the bolt 9 and at a pin 13. A resilient clamp 20 is pivotedbetween the side walls 11 and 12 of each frame 10 at points removed fromthe pivot points of the frame 10. Each clamp 20 consists of an elongatedpiece of resilient material, channel shaped in cross section, theopposite walls 21 and 22 of the channel consituting resilient opposedclamping flanges. At one end of member 20 is an ear 23 which is pivotedto the wall 11 of the member 10 on a pin 24. The opposite end of member20 has a flange 25 which is pivoted to the wall 12 at a pin 26, flange25 also having an offset resilient finger portion 27 which resilientlypresses against the wall 12. This finger portion has a small raisedpoint 28 which is adapted to snap into a depression 29 in the wall 12when the clamp is fully open to prevent the clamp from falling out ofplace on the frame 10 when the clamp is fully open.

As shown, there are two clamps 1 on each side of the hub 7. These clampsare exactly similar to each other except that the arrangement at theirends is reversed in order to adapt one for the right hand side of themachine and the other for the left hand side of the machine. Each clampat the side adjacent the side of the cylinder is provided with a springclip 30 which may be secured to the frame member 10 by means of asuitable clamp 31. I

In attaching a stencil stub 2 to the cylinder, the stub is first engagedwith the buttons 3 in the usual way. The clamping device being fullyopen, each clamp may be engaged with the button bar and stencil stub bygrasping the spring clip 30 and-pivoting it toward the stencil sheet.During this movement the frame 10 and clamp 20 pivot together toward thebutton bar until the fingers 21 of the clamp strike the top of thebutton bar or stencil stub thereon. The clamp will now be in theposition shown in Figure 4. Upon completion of the movement of clip 30into engagement with the stencil sheet the frame 10 continues to pivotand the clamp 20 pivots on the frame. This movement forces the clamp 20into engagement with the button bar and presses the stencil stub 5firmly againt the button bar 2. To release the clamp the clip 30 isgrasped and moved upwardly. This pivots the frame 10 in the reverseposition, first withdrawing the clamp 20 from engagement with the buttonbar and stencil stub and then swinging the clamp with the frame 10 intofully open position. To aid in releasing the clamp from the button barpressure of the operators finger may be placed on the forward end of thewall 11 of the frame 10, which wall is at the opposite side of the clampfrom the clip 30. In the construction shown, each clamp must be adjustedindependently of the other.

As many changes could be made in the above construction and as manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingshe interpreted as illustrative and not in a limiting sense.

What I claim is 1.'As an article of manufacture, a clamp of thecharacter described, comprising an elongated piece of resilientmaterial, channel-shaped in cross-section, the opposite walls of thechannel constituting resilient opposed clamping flanges.

2. The combination with an impression cylinder having a stencil stub barand a stencil sheet on the cylinder, of a pivotally mounted clamp havingopposed resilient jaws engageable with opposite sides of said bar toclamp'said stencil sheet thereto, substantially as described.

3. The combination with an impression cylinder having a stencil stubbar, of a pivotally mounted frame and a clamp pivotally mounted on theframe and swingable into and out of clamping engagement about said bar,substantially as described.

4. The combination with an impression cylinder having a stencil stubbar, a pivotally mounted frame, a clamp movable with the frame intoposition adjacent the bar, said clamp being pivotally mounted on saidframe whereby further movement of the frame forces the clamp intoclamping engagement with the bar, substantially as described.

5. The combination with an impression cylinder having a stencil stubbar, a pivotally mounted frame, a clamp movable with the frame intoposition adjacent the bar, said clamp being pivotally mounted on saidframe whereby further movement of the frame forces the clamp intoclamping engagement with the bar, and means for yieldingly holding theclamp against pivoting on the frame when the clamp is disengaged fromthe bar, substantially as described.

6. The combination with an impression cylinder having a stencil stubbar, a pivotally mounted frame, a clamp movable with the frame intoposition adjacent the bar, said clamp being pivotally mounted on saidframe whereby further movement of the frame forces the clamp intoclamping engagement with the bar, and means for pivoting the frame,substantially as described.

7. The combination with an impression cylinder having a stencil stubbar, a pivotally mounted frame, a clamp movable with the frame intoposition adjacent the bar, said clam being pivotally mounted on saidframe w ereby further movement of the frame forces the clamp intoclamping engagement with the bar, and a spring clip mounted on said barand constituting means whereby the frame may be ivoted manually,substantially as described:

8. The combination with an impression cylinder having a stencil stubbar, a pivotally mounted frame, a clam movable with the frame intoposition ad acent the bar, said clamp being pivotally mounted on saidframe whereby further movement of the frame forces the clamp intoclamping engagement with the bar. a flat spring engaging the cylinder,and a cam on said frame engaging said spring, said cam having fiatfaces, whereby the frame is held yieldingly in either of two positionswith respect to the cylinder, substantially as described.

This specification signed this 15th day of November, 1924.

ERNEST J. BRASSEUR.

